<!DOCTYPE html>
<html>
    <head>
        <title>{% block title %}My Website{% endblock %}</title> 
    <!--是定义的可替换区域-->
    </head>
    <body>
    <main>
        {% block content %}{% endblock %}
    <!--是定义的可替换区域-->
    </main>
    <footer>
        <p>Footer content</p>
    </footer>
    </body>

</html>